function call(e){
  var sc= document.getElementById("screen");
   var bo= document.getElementById("box1");
sc.innerHTML=bo.innerHTML;
document.getElementById("cl1").style.backgroundImage="url('../tab_image/active.gif')";
document.getElementById("cl2").style.backgroundImage="url('../tab_image/default.gif')";
}

function call2(e){
  var sc= document.getElementById("screen");
sc.innerHTML=document.getElementById("box2").innerHTML;
document.getElementById("cl2").style.backgroundImage="url('../tab_image/active.gif')";
document.getElementById("cl1").style.backgroundImage="url('../tab_image/default.gif')";
}




function setListeners(ev) {

 var clk= document.getElementById("cl1");
 var clk2 = document.getElementById("cl2");
 var clk3 = document.getElementById("cl3");
document.getElementById("box1").style.display="none";
document.getElementById("box2").style.display="none";

  var sc= document.getElementById("screen");
sc.innerHTML=document.getElementById("box1").innerHTML;
document.getElementById("cl1").style.backgroundImage="url('../tab_image/active.gif')";
document.getElementById("cl2").style.backgroundImage="url('../tab_image/default.gif')";

  addListener(clk, "click", call, false);
  addListener(clk2, "click", call2, false);

}


addListener(self, "load", setListeners, false);